Pre-surgical evaluation benefits from information about the location of functional brain systems and dysfunctional tissue. Recently, methods based on analysis of spontaneous activity measured by functional MRI have shown promise for identifying brain systems in subjects resting and while asleep. Here we will develop and evaluate a novel method using rest-state intrinsic activity to map multiple systems within the brain including language, memory, and motor systems. Specifically, this project aims to address three critical challenges in pre-surgical mapping. First, this project will seek to develop a new language and memory lateralization technique as a candidate to replace the traditional invasive Wada test. Second, we hypothesize that essential areas of cortex can be mapped using intrinsic functional connectivity linked to specific brain systems. Finally, by assessing the disruption of functional connectivity, we will seek to localize brain lesions and epileptogenic cortex. This project proposes a new approach for pre-surgical mapping for patients with brain lesions and has the potential to significantly improve surgical planning. PUBLIC HEALTH RELEVANCE: This project aims to replace the traditional pre-surgical mapping by providing a means to determine functional laterality, eloquent cortex and epileptic foci simultaneously and with minimal task requirements.